3D Trench Capacitor Coupling to Avoid Deep Trench Necking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor manufacturing processes face challenges in increasing the capacitance density of integrated passive devices (IPDs) due to limitations in trench depth, leading to issues like trench necking and reduced electrode surface area, which hinder the miniaturization of IPDs for mobile devices and application processors.
Innovation Solution
A three-dimensional (3D) trench capacitor design is implemented, where trench segments across multiple device layers are electrically coupled using hybrid bonding or through-substrate vias (TSVs), allowing for a high capacitance density by summing the capacitances of individual 2D trench capacitors while maintaining a small footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If trench depth is increased to improve capacitance density, then capacitance density is improved, but trench necking occurs and electrode surface area is reduced
Solution Approach 1:
The capacitor structure is divided into multiple separate trenches instead of a single deep trench. Each trench maintains a manageable depth that avoids necking issues while the collective arrangement of multiple trenches achieves the target capacitance density. This segmentation allows each trench to be manufactured with uniform shape and consistent electrode surface area.
2Quantity of substance
If trench depth is increased to improve capacitance density, then capacitance density is improved, but electrode surface area is reduced
Solution Approach 1:
The design transitions from relying solely on vertical depth to achieve capacitance to utilizing horizontal arrangement of multiple trenches. By distributing capacitance across multiple shallower trenches arranged in a planar pattern, the total electrode surface area is preserved and even increased compared to a single deep trench, while achieving the same or higher capacitance density.
3Area of stationary object
If IPD size is reduced for miniaturization, then device footprint is reduced, but manufacturing complexity increases
Solution Approach 1:
The IPD structure is segmented into multiple identical or modular trench units that can be replicated across the substrate. This modular approach allows systematic arrangement of trenches to achieve compact footprint while maintaining manufacturing simplicity through repetition of standardized structures rather than creating a single complex deep structure.
Data Source
AI summary
Various embodiments of the present disclosure are directed towards a three-dimensional (3D) trench capacitor, as well as methods for forming the same. In some embodiments, a first substrate overlies a second substrate so a front side of the first substrate faces a front side of the second substrate. A first trench capacitor and a second trench capacitor extend respectively into the front sides of the first and second substrates. A plurality of wires and a plurality of vias are stacked between and electrically coupled to the first and second trench capacitors. A first through substrate via (TSV) extends through the first substrate from a back side of the first substrate, and the wires and the vias electrically couple the first TSV to the first and second trench capacitors. The first and second trench capacitors and the electrical coupling therebetween collectively define the 3D trench capacitor.